The present disclosure generally relates to in vitro diagnostics and, in particular, to a system for processing sample tubes comprising a plurality of work cells for processing samples and to a method of processing sample tubes comprising withdrawing a volume of sample from a tube to be processed by the work cell and/or dispensing a volume of liquid into the sample tube.
Coming from diverse healthcare facilities, biological samples such as blood samples usually arrive in the laboratories in different kinds of tubes with various types of closures. These are typically primary sample tubes, so called because they are used to collect the samples, for example, by venipuncture.
There are instruments, which may process primary sample tubes without the need to remove the closure, i.e., by accessing the sample contained in the primary tube by piercing the closure with a pipetting needle, for example. Not all closures however are suitable for this procedure and not all types of instruments and/or analysis allow the use of this procedure. Some types of instruments and/or analysis require the primary tubes to be opened before samples are pretreated and/or analyzed. Therefore, such instruments should have an automatic decapper to automatically remove the closure from a primary tube.
Automated decapping of test tubes can be complicated by the variety of available primary tubes, which may vary in diameter, height, and especially the variety of available closures. Some closures have, for example, a thread for screwing on primary tubes. Another type of closure is a rubber stopper or cap, which may be removed by a pulling motion. The closures may also differ in their composition. They may be made of rubber, plastic, etc. Decapping devices that can decap, i.e., remove closures from, all or most of these types of primary tubes have been developed and are available on the market. These are typically modules integrated in a pre-analytical work cell, wherein one or more aliquots of a sample are withdrawn from a sample tube and transported in secondary tubes to one or more analytical work cells for being processed. The sample tube is then optionally reclosed either with the same closure or a new closure.
One alternative approach is to open the primary sample tube in a pre-analytical work cell and to dispose the original closure, to transport the opened tube to one or more analytical work cells for being processed and then to reclose the tube with a new closure, typically in a post-analytical work cell. One general problem is that the sample processing throughput is limited by the decapping and/or recapping throughput of the pre-analytical work cell.
Therefore, there is a need to increase sample processing throughput in a system comprising a plurality of work-cells enabling the opening, pipetting and reclosing to be more independent without the need for additional closures and without severe limitations on processing with a reduction of the costs and size of the decapping/recapping device allowing for a plurality of such devices in the same system.